Abstract:The formation of Ruoergai uranium mining field is extremely complex, mainly manifesting with high water sensitivity, strong broken and severe leakage, which result in high difficulty of drilling operation. In this article, combining the analysis on formation characteristics and the hole wall stability, the mud system suitable for the complex formation drilling in mining area is obtained, and good application results achieved in site. And a set of technical measures of mud maintenance and management are summarized in the application, which can be good reference for mud technology in similar complex formation drilling construction.

Abstract:In order to ensure a three-dimensional horizontal well to be drilled to the geological target safely and efficiently, the optimal design and research on trajectory of three-dimensional horizontal well was made by using COMPASS software. The design rules for the pre-target displacement of three-dimensional horizontal wells have been concluded by computer simulation study. The minimum longitudinal pre-target displacement was put forward. These provide the basis for the optimal design of the pre-target displacement of 3-D horizontal wells.

Abstract:Sand plug occurred in the fracturing process of low and middle rank coal reservoir in Baode block, which affected the reservoir reconstruction. Based on the geological features of this block, combined with the extension law of hydraulic fracturing in coal seams, the main factors caused sand plugging are analyzed, such as the increase of fracturing fluid loss caused by development of coal reservoir fractures and high permeability roof and floor fracturing and so on. The corresponding technical countermeasures are put forward on this basis, by using clean fracturing fluid, appropriately increasing and stabilizing the fracturing fluid displacement in construction and optimizing fracturing design, the reservoir reconstruction effect can be improved.

Abstract:Oilfield YD is one of marine strata carbonate reservoir in Middle East, active heterogeneous asphaltene heavy oil are distributed in Kazh formation with high pressure and acidic gas; being non-target layer, Kazh formation should be drilled through and isolated, then the lower payzone can be developed. Uneven distribution of asphaltene heavy oil and uncertain pore pressure bring severe challenges to drilling construction. Because of asphaltene heavy oil intrusion, 3 wells had to be abandoned in the first phase construction. In view of this world difficult problem, the technical study was made with some results. This paper discusses the experimental study on the intrusion mechanism of asphaltene heavy oil, the development of hardening agent, the application of managed pressure drilling technique and a series of associated technology research, proposes the safe drilling measures for asphaltene heavy oil layer and presents the field application effects.

Abstract:The failure of conventional drilling fluid system and multiple complex situations caused by deep reservoir with high temperature in Dingbei block, it is necessary to develop a set of drilling fluid with high temperature tolerance. Through analyzing the essentials of well drilling incident and the properties of potassium ammonium based drilling fluid, it is clear that the drilling fluid should be improved in high temperature inhibition, stability, filtration reduction and sealing ability. A lot of high-temperature drilling treatment agents have been tested in rheology, filtration, sealing and lubrication, SMC and SPHN are chosen as anti high temperature flirtation reducer, KCl and polyamine as anti high temperature inhibitor, HQ-10 as anti high temperature plugging agent, white oil and graphite as lubricant, SF-1 as anti high temperature diluent; the appropriate bentonite content is determined to be 4%, the high temperature drilling fluid system formula is finally obtained. The laboratory evaluation experiment shows that the viscosity, shear and water loss of this high temperature drilling fluid can still meet the design requirements after 180℃ hot rolling for 72h and anti-contamination of NaCl and CaCl2 are 10% and 4% respectively, the permeability recovery rate of damaged reservoir core can reach more than 80%. This high temperature drilling fluid formula will provide support to safe and effective drilling in Dingbei block.

Abstract:In 2015, gas hydrate trial mining horizontally butted well was constructed in Qilian Mountain Muli permafrost area, The formula of flushing fluid was designed optimally according to the formation conditions such as hydration, collapsing and chipping. Good wall protection and lubrication results were achieved by adjusting the dosage of drilling mud additives reasonably. Mud parameters such as density, viscosity, sand content, filter loss and some others were monitored in the application, and the properties of flushing fluid were timely adjusted. The application results show that the flushing fluid has good comprehensive properties and can meet the requirements of trial mining well drilling construction.

Abstract:In order to prevent lost circulation, increase the borehole wall stability and formation pressure, plugging material while drilling is usually added while drilling in permeable leakage formation, broken formation and low pressure formation. Especially in high temperature deep well, high temperature geothermal well and high temperature hot dry rock drilling, high temperature resistant plugging material must be added to drilling fluid. In this paper, the new progresses of high temperature resistant plugging material while drilling are introduced, including loss circulation agent while drilling based on bridge loss circulation material, expansive polymer plugging agent and ultra-low permeability agent. The composition and plugging mechanism of different high temperature resistant plugging materials while drilling were analyzed and the research direction of high temperature resistant plugging material while drilling was pointed out.

Abstract:Baiyanghe CBM pilot demonstration project in Fukang City of Xinjiang Uygur Autonomous Region is the first CBM demonstration project in Xinjiang. The general structure of Baiyanghe mining area is monoclinal structure in the direction of south with large dip angle, and large spacing in multi coal seams. Cluster wells are the main type for this demonstration project development plan. By many years drilling practice, this technology have been very mature in CBM block of east Ordos basin, a set of cluster wells drilling technology suitable for CBM development in this area is preliminarily formed. As the geological conditions in Baiyanghe mining area are quite different with east Ordos basin block, especially with the characteristic of large dip angle, multiple coal seams and large seam spacing, the cluster wells drilling technology in East Ordos Basin cannot be directly adopted. Based on the geological data, this paper analyzes the difficulties of CBM cluster wells drilling in Baiyanghe mining area, summarizes and expounds the technical countermeasures. The drilling technology of cluster wells suitable for Baiyanghe mining area has been developed.

Abstract:Being 2006.87m in depth, Wulanhada geothermal well was constructed with 30 type oil drilling rig in the Inner Mongolia Autonomous Region Chayouhou Banner, most drilled formations, more than 1500m, were metamorphic rocks, the roller bits were seriously damaged; and 18 times of coring were required for the construction. HJ637G roller bit was selected, the drilling efficiency per hour was up to 0.8～1.2m and the service life reached 80～100h. Chuan 7-4 double tube single rotary coring barrel was used, the core recovery could be 70%～95%.

Abstract:Cretaceous gravel layer, multilayer goaf and mud stone formation have been difficult for coalfield geological drilling. Firstly, it is easy to collapse due to the loose cementation at upper sand gravel layer hole section; secondly, strong water sensitivity, high swelling, joint and fissure development easily cause hole shrinkage, mud making and different degrees of leakage at lower hole section; thirdly, the wall protection in multilayer goaf. In view of the above, in the complex formation drilling in Datong coalfield, potassium ammonium polymer low solid mud is selected by repeated tests. The practice proves that the accidents of hole collapse, block falling, hole shrinkage can be prevented by using potassium ammonium polymer low solid mud to improve drilling efficiency and reduce cost.

Abstract:With the continuous increase of the geological core drilling hole depth, the hole accidents handling is more and more difficult. In order to shorten the construction period, particularly complex hole accidents are often given up, while a low-cost simple eccentric wedge is effectively used for directional drilling to bypass the accident section. This paper mainly introduces the simple eccentric wedge about its manufacture and the application in different drilling holes.

Abstract:The research is carried out on high quality and high speed drilling technology to solve low ROP, long drilling cycle and complex downhole instances of natural gas well in Fuxian block. The difficulties in drilling construction are summed up and analyzed; based on the study on rock drillability, by the cuttings rolling recovery experiment and agents screening experiment and combining with the field application, the drilling parameters are optimized. A group of bits are selected, which are applicable to the formation characteristics of this block with strong wear resistance and effective footage; bottom hole assembly is optimized with compound drilling of rotary table screw; potassium-ammonium polysufonate drilling fluid system are optimized to ensure downhole safety. Field practice shows that the average drilling cycle reduces 49.35% and the downhole accident reduces greatly, which provide the powerful technical support for high quality and high speed drilling in natural gas well of Fuxian block.

Abstract:Casing and liner running process is an important part of the whole drilling process. The traditional casing and liner running had to be slow and drilling fluid should be periodically grouted into pipe string; Especially for deepwater well and those wells with narrow density window of drilling fluid, it is difficult to control the suitable pipe string lowering speed and circulation loss is extremely easily caused by surge pressure. Casing and liner fast running technology is being studied to improve operation efficiency, ensure downhole safety and satisfy the requirements of drilling process. This paper introduces casing and liner fast running technology about its main principles, characteristics, tools and operation method, as well as the field application and some attentions, analyzes and summarizes some difficulties which might occur in operation and puts forward corresponding suggestions, which can be reference to the similar deepwater well drilling operation.

Abstract:Generally, it is unnecessary to control wellhead pressure in geological exploration drilling, while for Yang D 1 well in Jinlingsi Yangshan basin of west Liaoling, the oil and gas exploration was carried out with the drilling method of geological exploration wells, wellhead pressure control measures should be prepared, and the coupling of geological drilling equipment and well control device is the focus of this paper. Take this well as the example, the construction process of oil and gas exploration well with full hydraulic core drilling rig for full hole diamond core drilling is presented. The space dimension below YDX-6 full hydraulic core drilling machine platform, casing program design, wellhead pressure control and some other requirements were taken into account in drilling operation, a set of well control equipment is determined and designed, which can meet small-diameter core drilling construction.

Abstract:Clamping and unclamping device is one of the most important composition parts on double-tube drilling rig. It is mainly used for drill pipe clamping and unclamping combined with the rotary mechanism, the stand or fall of its performance will directly affect the performance of the whole machine, drilling efficiency and quality. ABAQUS software has been used for the finite element analysis and optimization of clamping and unclamping device in order to shorten the development cycle and ensure the function and quality of the design. The results show that the optimized structure could meet the demands of safety factor, and could provide the guarantee to the reliability of the clamping and unclamping device and the integral performances of the double-tube drill.

Abstract:The electric control system is the core of operation control for a rig, its high security and reliability are the important guarantee for the normal operation. A scheme of control system based on CAN bus technology is proposed in this paper, the system structure and function design are discussed. Through its application on SDC2500 vehicle-mounted hydraulic, it is proved that this control system based on CAN bus technology has advantages of simple wiring, remote integrated control, fault early warning and improved drilling rig safety.

Abstract:The underground canteen of Beijing No.55 Middle School is adjacent to the basement structure of a classroom building at the north side, no space was remained for retaining pile because of the site restriction in the north of underground canteen foundation pit, and soil nailing wall support cannot meet the strict requirements of surroundings on the displacement and settlement of excavation. In this case, an embedded “pre-stressed anchor ribbed plate wall” was designed and adopted to replace the pile-anchor support structure. Combined with the engineering case of foundation pit support, this paper introduces the parameters design and construction measures for the pre-stressed anchor and ribbed plate wall structure.

Abstract:The comparison analysis is made in detail on the wall by TRD method and cut-off wall by slot machine in construction cost, work efficiency, anti-seepage quality, environmental protection and consumptive material. The results show that cut-off wall is better than TRD method wall under the same conditions, which is an advanced and feasible waterproof construction technology and deserves popularization and application in the ultra deep foundation pit waterproof.

Abstract:Being restricted by the environment and according to the urban planning, some HV cables have to be laid under the existing buildings or pipelines, the values taking for safety distance should be calculated in the trajectory design. In this paper, a case of directional drilling project is discussed, which is 110kV HV transmission cable line in Xiamen. According to the existing technical codes in China and based on the engineering cases investigation, the analysis was made on the influencing factors on the safety distance value taking for electric power cable protection pipe laying to optimize the pipe laying trajectory. Xiamen 110kV HV cable protective pipes have been laid successfully under the ground, which can provide references for similar construction.

Abstract:For the investigation and monitoring of groundwater, appropriate sampling methods should be selected according to the conditions of the survey site and the purpose of the investigation and strictly follow the sampling operation procedures in order to obtain real and representative samples. On the basis of sorting out the common ground water sampling methods and sampling apparatus, this paper introduces the compiling process of the industry standard "groundwater sampling technique regulation" and the main contents. The regulation content involves sample collection requirements, sampling methods, samples storage and quality control of groundwater field test samples, inorganic and organic test samples, gas test samples, isotope test samples and the specific samples such as geothermal water and drinking mineral water samples.